In general, for an elevator hoisting machine brake, a braking force is produced by cutting the power supply to a brake coil by an electromagnetic switch. When there is only one electromagnetic switch, in a case where an ON failure of the electromagnetic switch occurs, the brake cannot perform a braking operation. Therefore, in order for the brake to reliably perform a braking operation, a plurality of electromagnetic switches are needed.
Hitherto, an elevator brake safety control apparatus has been proposed in which operation of a semiconductor switch in a primary-side circuit of a direct current (DC)-DC converter for supplying power to a brake coil is controlled by a pulse-width modulation controller so that the power supply of the pulse-width modulation controller is cut at a plurality of safety relay contact points when an abnormality occurs in the elevator (refer to Patent Literature 1).